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Re: open transport protocol for aysnc web services?

From: Mark Nottingham <mnot@akamai.com>
Date: Mon, 9 Jul 2001 12:47:37 -0700
To: Mark Baker <distobj@acm.org>
Cc: www-ws@w3.org
Message-ID: <20010709124732.B30080@akamai.com>
On Mon, Jul 09, 2001 at 03:06:29PM -0400, Mark Baker wrote:
> 
> When they launched a couple of weeks ago, they put up their
> documentation at developer.knownow.com.  Check it out.

Cool; thanks.

> They also use a persistent HTTP 1.1 GET connection to implement
> subscription semantics.  The router responds with the event
> notifications on the response stream of the GET, so long as the
> connection is up.
[..]
> I wouldn't say that they're breaking anything.  As their message
> exchange pattern is asynchronous, it matters not that the "request" and
> "response" streams don't necessarily traverse the same proxy.

It's not so much that as the decoupling of the request and response.
In other words, if they make a request, keep the persistent
connection open, and then send responses upon events, the 1->n
request/response relationship will confuse proxies. Of course, this
won't be the case if they keep a 1-1 relationship (perhaps by doing
request...response,request...response,request...).

However, using persistent connections in this manner isn't too
friendly to proxies; it consumes resources on them, and many will
close idle connections after a fairly short timeout. When this
happens, it becomes inefficient to use the HTTP, as you have to
continually re-establish the connection.

Cheers,

-- 
Mark Nottingham, Research Scientist
Akamai Technologies (San Mateo, CA USA)
Received on Monday, 9 July 2001 15:47:40 GMT

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